Share 'Facts about can lighting energy consumption'

I've been searching the web, including sites dedicated to energy efficiency in residential building, and I cannot find substantiated facts related to how much energy Recessed Can Lights consume.  I'd love to see comparisons of non-IC, IC, and ICAT cans regarding measurable facts on how their air leakage contributes to energy usage.  The only study I can find is from Penn State University that was…